Arrangement in rapid reclosing compressed air circuit breakers



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ARRANGEMENT IN RAPID RECLOSING COMPRESSED AIR CIRCUT BREAKERS Filed Jan.17, 1948 Patented Oct. 30, 1951 ARRANGEMENT IN RAPID Riser-losing ooM-PREssED AIR CIRCUITA BREAKERS Haakon Forwald; Valhalla, Ludvika, Sweden,as'- signor to Allmanna SvenskaElektris'ka Aktiebolaget, Vasteas,Sweden, a' Swedish corporation Application January 17, 194s, serial No.2,915 In Sweden .uly 17, 1943 Section 1, Public Law 690, August 8, 1946'Patent expires July 17, 1963 3 Claims.

In compressed air circuit breakers with rapid reclcsing it is often notnecessary at occurring faults to interrupt all phases, it generallybeing suicient to interrupt the phase, where the fault occurs, whereasif the fault remains, all phases are interrupted.

The present invention has for its object such a rapid reclcsing circuitbreaker separately interrupting the phases and is characterized therebythat when a breaking impulse arrives all extinguishing chambers areimmediately lled With compressed air. At the first interruption, onlythe faulty phase is opened, but if the fault after reclcsing remains,all breaking gaps are opened. The arrangement is combined with theadvantage that at the denite interruption all breaking chambers are lledwith compressed air ready to perform the extinction. After fullledinterruption and after opening of the disconnecting switches connectedin series with the breaking gaps the extinguishing chambers are emptiedand their contacts returned to the closed position. The valvecontrolling the extinguishing air can either be common for all phases ora separate valve may be arranged for each phase.

On the accompanying drawing, one form of the invention is shown in across-sectional view with a separate air valve for each extinguishingchamber. The left-hand phase is illustrated in open position, thecorresponding controlling contacts 8 being closed, while the middle andthe right-hand phases are shown in closed position with theircontrolling contacts 8 in open position. The compressed air is deliveredto the extinguishing chambers I from the containers 2 through the airvalves 3 which are opened by means of the air valves 9, when, by closingof the contact 5, the operating coils 4 of the valves 9 are energized.The contacts 5 are closed by the actuating coil I0, which is energizedWhen a fault occurs or when the circuit breaker otherwise should beopen. After the extinguishing chambers I have been lled With compressedair, the interruption is eiected by delivery of compressed air to thedilerent operating pistons I I through the valves '6, which are openwhen the contacts 8 are closed, so that the coils 'I become energized.This can be done either in one or in a plurality of phases, so that thecontacts I2 are separated either in one or in a plurality ofextinguishing chambers I.

Upon reclosure, the contacts 8 which have been closed are opened again,so that the breaking gap in the corresponding extinguishing chamber isclosed again. Obviously, none of the contacts 2 8 can energize the coils1 prior to the closing of contacts 5.

If the disturbance remains after the reclosure, the contacts I2 in allextinguishing chambers I generally are opened, the arrangement beingsuch that then all contacts 8 are closed. After the disconnecting switchnot shown in the drawing but coupled in series with the circuit breakerhas been opened, the contact 5 and all contacts 8 are opened again, sothat the extinguishing chambers i are emptied from compressed air and sothat the contacts I2 therein are again closed.

In the operation of this circuit-breaker, the contacts I 2 of one ormore of the phases are opened by the delivery of compressed air throughvalves 6 to the corresponding piston or pistons II, but the arrangementis such that actuation of these pistons to open the contacts I2 is notpossible until the contacts 5 have been closed and compressed air hasthus been caused to pass from the containers 2 to the chambers I of allof the phases, so that opening of the contacts I2 before compressed airis available in the arcing chambers is prevented. If the fault persistsafter the closing of the contacts I2 that have been openened, thecontacts I2 in all phases are then opened by the closing of the contacts8. For the subsequent reclcsing of the contacts I2, it is necessary onlyto simpltaneously open all the contacts 8, so that the air pressureabove the pistons II is relieved and the contacts I2 are all closedsimultaneously.

I claim as my invention:

l. A rapid reclcsing multi-phase air blast circult breaker, comprisingair blast extinguishing chambers, breaker contacts in said chambers,means for the simultaneous control of the delivery of extinguishing airto said chambers of all the phases, means for the individual control ofthe breaker contacts in each phase independently of the contacts in theother phases, and means whereby the opening of any of the breakercontacts is prevented until compressed air has rst been delivered tosaid extinguishing chambers.

2. A rapid reclcsing multi-phase air blast circuit breaker, comprisingair blast extinguishing chambers, breaker contacts in said chambers, anelectrically operated air blast control valve for the admission of airto said chambers individually for each phase, an electrically operatedair valve for the individual operation of the breaker contacts of eachphase, common operating contacts for all said air blast control valves,individual operating contacts for each breaker contact operating airvalve, said individual contacts permitting 5 individual opening of thebreaker contacts, and electrical connections whereby operating currentis fed to said individual operating contacts only when said commonoperatingvcontacts are closed.

3. A rapid reclosing multi-plase air blast circuit breaker, comprisingair blast extinguishing chambers, breaker contacts in said chambers, anelectric switch for the simultaneous control of the delivery ofextinguishing air to the said chambers of all the phases, an individualswitch for the control of the operation of the contacts in each phase,electrical connections feeding electric current to all said switches andpreventing the passage of current through said individual l5 switchesand the opening of said breaker contacts before the closing of the 'rstmentioned 4 switch and the delivery of compressed air to the chambers.

- HAAKON FORWALD.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS

